We propose to develop and thoroughly test in-vivo, a commercially viable time-multiplex-based telemetry system suitable for short-range telemetry of biopotentials from animals as small as adult rats. This approach was chosen as a result of the Phase I effort involving a feasibility assessment of several alternate approaches based on market needs and engineering design considerations. We will enhance the capabilities and miniaturize the transmitter prototyped in Phase I, develop a compatible receiver, and enhance our existing data acquisition system capabilities to provide a complete system for telemetering and acquiring high-frequency biopotentials. This will be the first commercially available system to allow multi-channel wireless monitoring of EEG, EMG, and single unit potentials in small laboratory animals. The system will allow laboratories involved in basic research, toxicological testing, and the evaluation of pharmaceutical compounds to collect data which are more definitive and less artifactual while using protocols which require fewer animals. Commercial markets for this device include academic, pharmaceutical, and government laboratories in addition to independent testing firms and chemical companies involved in the assessment of the toxic effects of chemicals.